diff options
| -rw-r--r-- | include/linux/pagemap.h | 15 | ||||
| -rw-r--r-- | mm/filemap.c | 17 | ||||
| -rw-r--r-- | mm/page-writeback.c | 2 |
3 files changed, 33 insertions, 1 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 0a2f5d2..64f9509 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -130,14 +130,29 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma, } extern void FASTCALL(__lock_page(struct page *page)); +extern void FASTCALL(__lock_page_nosync(struct page *page)); extern void FASTCALL(unlock_page(struct page *page)); +/* + * lock_page may only be called if we have the page's inode pinned. + */ static inline void lock_page(struct page *page) { might_sleep(); if (TestSetPageLocked(page)) __lock_page(page); } + +/* + * lock_page_nosync should only be used if we can't pin the page's inode. + * Doesn't play quite so well with block device plugging. + */ +static inline void lock_page_nosync(struct page *page) +{ + might_sleep(); + if (TestSetPageLocked(page)) + __lock_page_nosync(page); +} /* * This is exported only for wait_on_page_locked/wait_on_page_writeback. diff --git a/mm/filemap.c b/mm/filemap.c index b9a60c4..d5af1ca 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -488,6 +488,12 @@ struct page *page_cache_alloc_cold(struct address_space *x) EXPORT_SYMBOL(page_cache_alloc_cold); #endif +static int __sleep_on_page_lock(void *word) +{ + io_schedule(); + return 0; +} + /* * In order to wait for pages to become available there must be * waitqueues associated with pages. By using a hash table of @@ -577,6 +583,17 @@ void fastcall __lock_page(struct page *page) } EXPORT_SYMBOL(__lock_page); +/* + * Variant of lock_page that does not require the caller to hold a reference + * on the page's mapping. + */ +void fastcall __lock_page_nosync(struct page *page) +{ + DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); + __wait_on_bit_lock(page_waitqueue(page), &wait, __sleep_on_page_lock, + TASK_UNINTERRUPTIBLE); +} + /** * find_get_page - find and get a page reference * @mapping: the address_space to search diff --git a/mm/page-writeback.c b/mm/page-writeback.c index b9f4c6f..5557529 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -701,7 +701,7 @@ int set_page_dirty_lock(struct page *page) { int ret; - lock_page(page); + lock_page_nosync(page); ret = set_page_dirty(page); unlock_page(page); return ret; |